I own this phone since november last year, and for the things you just posted, YES it's worth, i have linked on it Google Mail, Facebook, Twitter, and the gps is good.
The phone is stable, doesn't have glitches (just the market which lots of people start to have it, but it can be fixed easy)
And besides, it has TIMESCAPE witch you can set it to facebook stats, if you do that, it will show all the updates on your wall, if you enter the app, or if you set it as widget.
p.s. Good buy!
p.s.2 I play angry birds on it, no probs :P
Skype is fine! download it for free on the market, log in. and enjoy!
p.s. what you chat on your pc, it will appear on your phone after you log in, you can change that from settings.
p.s.2 makeing a skype call to a friend from the phone is also ok, the quality is higher than the normal network provider.